The World Doesn’t Need Any More Nuclear Strategies

A nuclear bunker in Northern Ireland on February 4, 2016. (Charles McQuillan/Getty Images)

The non-use of nuclear weapons since 1945 is a great achievement that we take for granted all too often. Although the number of states possessing nuclear weapons has slowly increased over the past seven decades, no country has used a nuclear weapon since 1945, and despite some worrisome incidents, I know of no case where a nuclear-armed state ever came really close to firing a nuclear bomb at another country. Continuing this lucky streak for as long as possible — ideally, forever — should be a paramount goal for all human beings.

There are a number of obvious reasons why nuclear weapons have never been used. Attacking another nuclear-armed power is obviously foolhardy, because it risks one’s own destruction and because no political gains could possibly be worth the costs of being hit by even a handful of nuclear bombs in retaliation. It is possible to attack nuclear-armed countries with conventional forces — as Egypt and Syria did in the 1973 Yom Kippur War — but if you do, your aims had better be limited and you must take care not to threaten the survival or independence of the state you’ve attacked. Using a nuclear weapon to attack a non-nuclear state would also be very costly to the attacking country’s reputation, unless the non-nuclear state had done something truly horrible and seemed likely to continue doing it. The good news is that one does not have to be very smart or perfectly rational to figure these things out.

The extensive efforts to prevent nuclear proliferation have also made nuclear use less likely. Although this campaign could not stop a few additional states from joining the nuclear club, it ensured that this process occurred gradually and allowed other states time to adjust. Over time, improved command-and-control and other security arrangements made accidental or unauthorized use less likely, and the emerging “taboo” against nuclear use probably reinforced non-use as well. Instead of thinking of nuclear weapons as just a bigger bomb, both politicians and weapons experts actively worked to place these fearsome weapons in a special conceptual category, thereby increasing the political costs of crossing that particular threshold. And humankind also got lucky, insofar as there have been a few moments since 1945 when things might have gone differently.

I raise all this because nuclear weapons are back in the news. One reason, of course, is the widespread concern about North Korea’s advancing nuclear and missile capabilities. Officials in the Donald Trump administration have repeatedly said it is unacceptable for North Korea to have the capacity to strike the American homeland, and their attempts at saber-rattling — such as talk of a so-called bloody nose strike — have raised fears that a real shooting war might break out on the Korean Peninsula.

A second reason is the partial release of the Pentagon’s new Nuclear Posture Review, which lays out an ambitious and costly proposal for modernizing the U.S. nuclear arsenal. The modernization plan is not intended merely to ensure that U.S. nuclear weapons remain reliable and secure (which is a perfectly reasonable objective); rather, the Pentagon also wants to develop a new generation of smaller nuclear weapons and more flexible targeting abilities, so that actual nuclear use becomes more feasible. This step is necessary, or so the planners say, to address an increasingly complicated strategic environment and certain low-level nuclear options that Russia is said to be developing. In short, the Posture Review is recommending not just the prudent preservation of an effective deterrent; it also wants the American taxpayer to pay for a lot of expensive new ways to use a nuclear bomb. Not because its authors want to fight a nuclear war, mind you, but because they believe having this capability will make their country more secure.

Full disclosure: I’ve always found such discussions slightly baffling. I used to spend a lot of time thinking about these issues, and I taught classes on nuclear strategy and arms control at the start of my teaching career. I don’t focus as much on the subject nowadays — my bad — but I’ve kept up with a lot of the literature, and I have yet to read anything that has altered my belief that nuclear weapons have no real political value except as a deterrent against direct attacks against a state’s home territory and/or truly vital overseas interests. They’re no good for blackmail or coercion, they don’t confer as much geopolitical status as proponents believe, and they certainly don’t allow their possessors to dictate terms to weaker and non-nuclear-armed opponents. If nuclear weapons gave their possessors lots of leverage, for example, dealing with leaders like Slobodan Milosevic, Saddam Hussein, Muammar al-Qaddafi, or Bashar al-Assad (not to mention the Castros in Cuba or the Kims in North Korea) would have been a lot easier.

Moreover, I find the elaborate scenarios that nuclear strategists dream up to justify new weapons to be both militarily and politically unrealistic. They tend to assume that complex military operations will go off without a hitch the very first time they are attempted (and in the crucible of a nuclear crisis), and they further assume that political leaders in the real world would be willing to order the slaughter of millions for something less than existential stakes. My main concern has been that some gullible politician would actually believe that one of these elaborate scenarios would actually work and might therefore be tempted to try it. Just as bad: An adversary might think the United States thought it could win such a war and might decide it had no choice but to try to hit it first.

I also find the obsession with matching capabilities at every rung of some hypothetical “escalation ladder” to be slightly absurd. Is it realistic to think that U.S. leaders defending vital interests against a possible Russian threat would be stymied because they didn’t have a capability that exactly mirrored whatever Russia had or was threatening to do? Would a top advisor really say to the president: “Oh dear, sir, Russia just threatened to attack with a nuclear weapon with a yield of 7.2 kilotons. We have lots of 5-kiloton bombs and lots of 11-kiloton bombs all ready to go, but if we use the little one, they’ll think we’re wimps, and if we use the big one, then the onus of escalation will be on us. I guess they’ve got us over the whing-whang, sir, and we’ll just have to do whatever Putin says. If only we had built more 7.2 kiloton bombs than they did!”

With all that as background, I have a few questions about the new direction the Pentagon is proposing, along with a few provisional answers of my own.

Question 1: Exactly how does the more modern nuclear arsenal proposed by the Nuclear Posture Review make the United States safer?

Answer: Apart from ensuring that the U.S. arsenal remains reliable, it doesn’t.

As things stand now, nobody really doubts America’s deterrent capability: Its arsenal is already a lot more potent than anyone else’s. Moreover, nobody really doubts its ability to blow things up all over the world without using a nuclear bomb, including some pretty hard targets. The United States has been conducting drone, air, and cruise missile strikes in lots of places for many years now, and it has even used the GBU-43/B Massive Ordnance Air Blast (the largest conventional bomb in the U.S. arsenal) against the Islamic State in Afghanistan.

So, what is the strategic problem that these new capabilities are going to solve? Do they really expect Russia or China or Iran or other adversaries to give up vital interests because the United States acquires a slightly more flexible set of strategic capabilities? Is there any country on earth that is looking at the current U.S. arsenal and saying to itself: “Gosh, attacking America or one of its allies would be easy today, but if they get some smaller nukes and more flexible options, then we’ll have to abandon our entire plan of world domination!” Are other countries likely to be significantly more intimidated by U.S. development of nuclear bombs that are bigger than the Massive Ordnance Air Blast but smaller than its existing nuclear weapons? Will violent extremists like al Qaeda or the Islamic State suddenly cease their activities after the United States upgrades its ability to put a thermonuclear weapon in more places more rapidly? Will any of these new features boost the U.S. economy, slow climate change, reduce inequality, make the United States more popular around the world, or restore the confidence in U.S. judgment that has been lost under Trump? The questions answer themselves.

Question 2: Why doesn’t the United States have more faith in nuclear deterrence?

Answer: Because threat-inflators are more numerous than threat-deflators.

A striking irony in most discussions of America’s nuclear posture is how little confidence Americans seem to have in it. No matter how much the United States spends on nuclear forces, official Washington doesn’t really believe they will achieve the aim for which they were bought. The United States has spent several trillion dollars on nuclear weapons since the Manhattan Project, and today it has the world’s most capable nuclear arsenal. Even if the United States were attacked first, the 1,500-plus warheads that are presently deployed are capable of destroying any society on earth in a retaliatory strike. Yet somehow these vast powers aren’t enough to make the United States confident it can take on much weaker nuclear powers, such as North Korea. President Donald Trump boasts that his “button” is bigger than North Korean leader Kim Jong Un’s, but official Washington acts as if the opposite were true.

This position has never made much sense. America’s nuclear deterrent was apparently good enough to keep mass murderers and ideological zealots such as Josef Stalin, Mao Zedong, Nikita Khrushchev, and Kim Il Sung from attacking the United States, and it discouraged them from threatening key U.S. allies, but apparently the United States cannot quite believe that it is enough to convince a weaker adversary like Kim Jong Un. Kim is hardly someone to admire or trust, but he shows no signs of being suicidal, and there’s no reason to think he isn’t fully aware of what the consequences of attacking the United States (or South Korea) would be. Ironically, the more visibly Americans fret about it, the more he might be led to believe that maybe his modest arsenal really is politically potent. Needless to say, that is hardly the conclusion the United States wants him to reach.

Question 3: Why is it in the U.S. interest to lower the nuclear threshold?

Answer: It’s not.

By calling for smaller-yield weapons and more flexible nuclear targeting abilities, the Nuclear Posture Review deliberately seeks to lower the nuclear threshold. It wants the United States to acquire capabilities that will make other states think the United States can use these weapons more readily in the future, in the hope that this capability will make those states more inclined to do what it wants (or not to do what it doesn’t want).

But there are big risks to lowering the nuclear threshold. Rather obviously, making nuclear weapons more usable makes it more likely that they will in fact be used — sooner or later. And because the United States has no idea how other states will respond once the nuclear threshold has been crossed, making nuclear use more likely is a social science experiment it really does not want to run.

More importantly, having an improved war-fighting capability — and in particular, the clear potential to disarm an adversary — risks putting that adversary in a “use or lose” situation. If an enemy thought the United States was willing to use nuclear weapons first and believed it had lots of options for doing so (including a disarming first strike), then it might be tempted to preempt, especially in a serious crisis. And remember: No one is likely to even think about using nuclear weapons unless the stakes are pretty high. If an adversary thinks its existence or even its long-term power position is at risk, does the United States really want it thinking it will lose big if it waits? As we have understood since the seminal writings of Albert Wohlstetter and Thomas Schelling, threatening an adversary’s deterrent is a bad recipe for crisis stability, and making nuclear crises harder to control is hardly in America’s interest.

Question 4: What does this mean for America’s anti-proliferation efforts?

Answer: Nothing good.

The new Posture Review sends a clear message to the rest of the world. It says that even if you are a continent-sized superpower with the world’s largest economy, the world’s most powerful conventional forces, no enemies nearby, and no powerful adversaries openly seeking to overthrow your government, you still need lots and lots of highly sophisticated and expensive nuclear weapons in order to be secure. Unfortunately, that message will make it pretty damn hard to convince far weaker and more vulnerable countries like North Korea or Iran that they don’t need nuclear weapons to be safe, and it will make it harder to convince countries like China or Russia that they have no need to build up sophisticated war-fighting capacities of their own. From a long-term perspective, this approach seems rather short-sighted.

And how’s a country like Estonia or even Sweden supposed to feel?

To be clear: I don’t expect to see radical nuclear disarmament in my lifetime, and I don’t expect to see a nuclear bomb being fired, either. I think nuclear weapons have made large-scale war less likely, and I’d support a well-thought-out effort to ensure that U.S. nuclear forces are both reliable and safeguarded against interference, theft, or accidental use. (In this regard, it is worth remembering that the Barack Obama administration had also proposed a significant modernization program, albeit one that was less costly and dangerous than what Trump & Co. seem to have in mind.) But instead of giving the bomb a more prominent role in U.S. strategy, and taking steps that lower the nuclear threshold in dangerous ways, I’d like to see them reserved for the only task for which they are really suited: deterring direct attacks on the U.S. homeland and other vital U.S. interests. That’s probably one of the many reasons why I don’t occupy a prominent place in America’s strategic nuclear priesthood.

About the Author

Stephen M. Walt is the Robert and Renée Belfer professor of international relations at Harvard University.

Stephen M. Walt is the Robert and Renée Belfer professor of international relations at Harvard University.